Numerical modeling of the effect of concrete porosity evolution on electrochemical chloride removal from concrete structures

Abstract

Porosity evolution caused by electrochemical chloride removal (ECR) process can affect the transport behaviour of concrete and vice versa. The main task in this investigation is to quantitatively understand the porosity evolution effect on ECR process, and find a more accurate model that gives good correlation with the experimental results concerning the ionic transport in concrete during the ECR. The porosity of the concrete near the cathode and anode were measured, before and after ECR treatment (mainly 7 days, 15 days and 30 days). A method to analyse and calculate the porosity profiles was proposed according to the ECR experimental data. The penetration and leaching of ionic species in concrete are studied by using a finite element procedure based on the Nernst–Planck equations. The proposed method is capable of reducing the numerical modelling error of the chloride profile in concrete during the ECR.